There are applications where a group of gas pressures are required that are accurately related to each other, as in the testing of transducers. The usual approach in monitoring such pressures is to use a group of manometers, each being used to measure one of the pressures, or to use a single monometer connected in turn to each of the pressures. Manometers containing mercury are often used. The height of a column of mercury in a transparent tube can be measured by comparing the top of the column to gradations etched in the tube. However, it is difficult to determine precisely where the top of the column lies with respect to a marking, because of the meniscus at the top of the column. A lighter manometer liquid such as water is also used, which enables greater precision in measurement. For most measurements of pressures, water columns are too high to enable their inclusion in compact instruments. Even a mercury column may be too tall for inclusion in a compact instrument where the highest pressure exceeds 3 psi. For example, to measure a pressure of 300 torr (about 6 psi) requires a mercury column whose top is about 360 mm tall (about 14 inches). A manometer arrangement which substantially reduced the height required for manometers to be used for measuring two or more pressures, while also enhancing the accuracy of comparative measurements of the tops of manometer liquid columns with respect to markings and to each other, would be a considerable improvement.